Presentation #622.14 in the session Protoplanetary Disks - Theory.
Planetesimals are 1-100 km bodies that are the building blocks of planets. There is growing evidence that planets and planetesimals begin to form very early, during the Class 0/I stage, when infall from the pre-stellar core and disk self-gravity dictate the structure of the circumstellar disk. We seek to understand how dust growth occurs in the first 1 Myr and how it sets the conditions for planetesimals to form early. We modified DustPy to build a 1D model of a circumstellar disk that models infall from the pre-stellar core as well as the gravitoturbulent stress of a Class 0/I disk. We explore the role of magnetic breaking in the growth of the disk and implications for planetesimal formation. Magnetic braking zaps angular momentum from infall and leads to the formation of a decretion disk in the earliest stages. In young, massive, circumstellar disks, disk self-gravity leads to the formation of gravitoturbulence, which can be the dominant source of accretion in the earliest stages. We explore how magnetic braking and gravitoturbulence determine the evolution of the disk itself, its thermal structure, and the evolution of dust grain sizes, with a focus on what it means for planet formation: We trace grain growth tracks and test them against the requirements for planetesimal formation by the streaming instability. We follow the evolution of the water and CO snowlines, and track the local cooling time to determine which regions of the disk may be susceptible to particle trapping in vortices formed by the Vertical Shear Instability (VSI) or Convective Overstability (COV).